We have to be able to simplify expressions of the form
and 
We must be clear about the rules for indices and cancelling fractions.
The first one is simplified as follows:
The second expression factorises on the top and bottom:
is a common factor hence we can cancel it to give the answer:
We may also have to simplify by adding fraction which result in terms to cancel:
The numerator factorises and we can identify common factors in numerator and denominator.
